A compound to be an effective stabilizer in protecting a polymer substrate must remain in the substrate during processing and end-use conditions. One method of assuring this is to chemically bond the stabilizer to the polymer substrate backbone in some fashion. U.S. Pat. Nos. 4,145,512 and 4,178,279 describe polyurethane stabilized by incorporating 2,2,6,6-tetramethylpiperidine derivatives which contain amino, hydroxy or hydrazide moieties into the urethane prepolymer solution.
P. A. Callais et al, Proc. Water-Borne High Solids coating Symp., 16, 486 (1989) describe N-(2,2,6,6-tetramethylpiperidin-4-yl)-N'-aminooxamide and N-(1-acetyl-2,2,6,6-tetramethylpiperidin-4-yl)-N'-aminooxamide reacted with acrylic polyors containing anhydride functionality. U.S. Pat. No. 4,730,017 teaches N-H, N-alkyl and N-acryl substituted 4-oxamido-2,2,6,6-tetramethylpiperidine derivatives bearing hydroxy groups.
None of the above references describe compounds having 1-hydrocarbyloxy groups present.
Specific 1-hydrocarbyloxy piperidine derivatives bearing a reactive functional groups have been described for applications other than polymer stabilization. N-Benzyloxy-4-hydroxy-2,2,6,6-tetramethylpiperidine has been detected during the photolysis of 4-hydroxy-1-oxyl-2,2,6,6-tetramethylpiperidine in toluene (J. F. W. Keana, J. Org. Chem, 36, 209 (1971)). The N-(2-cyanopropan-2-yloxy)-piperidine derivative ##STR1## has been used in a study of nitroxyl radiosensitizers (B. C. Millar et al, Radiat Res, 88, (1981)).
The 1-hydrocarbyl(oxy) groups of the instant compounds contain only carbon and hydrogen.
1-Hydrocarbyloxy hindered amine derivatives are described in copending patent applications with Ser. Nos. 259,956; 099,418; 259,950; 259,958; 259,945; 259,944; 259,952; 259,949; 259,955 and 259,946.